1. Field of the Invention
The present invention relates to a touch-control display technology, and in particular to an embedded optical induction input device and an embedded optical induction input method.
2. The Prior Arts
Nowadays, touch-control panels are the most simple, direct, and efficient means of communications between users and electronics devices, thus, they have become very popular and are widely utilized. As such, touch-control panels operated under various operation principles are developed and commercialized. Among them, the most commonly used touch-control panels include: capacitor type, resistor type, sonic wave type, infrared light type, and in-cell (embedded) type touch-control panels, etc. Wherein, the development of in-cell (embedded) touch-control panels is getting most of the attentions. Compared with the conventional resistor or capacitor type touch-control panels both requiring additional touch-control panels to be installed on the associated display panels, for an in-cell (embedded) touch-control panel, the touch-control function is built-in and incorporated into a display panel without additional touch-control panels. Therefore, it has the advantages of light-weight, small size, and high optical performance, and thus is held in high esteem in the industry.
Presently, most of the in-cell (embedded) touch-control panels are of an optical sensor type, wherein, a photo sensor embedded in a display panel is used to detect the light intensity distribution on a panel in determining a touch-control-position event, and in such a process, the photo sensitivity amorphous silicon material is utilized, while such photo sensors can be the amorphous silicon thin-film-transistor (a-Si TFT) sensors produced directly by utilizing the existing manufacturing process and equipment. Moreover, according to the different light sensing principles, the light sensing circuit can be classified into a charge mode and a current mode. As shown in FIG. 1, while in a charge mode, a first transistor 10 is turned on, thus charging a storage capacitor (Cst) 12, next, the first transistor 10 is turned off, and then a part of the charges in the storage capacitor 12 will be leaked out due to a photo current flowing through a second transistor 14. As the light intensity is getting stronger, the charge leakage is getting faster because the photocurrent is proportional to the light intensity. Afterwards, the first transistor 10 is turned on again to read the charges remaining in the storage capacitor 12 in determining a touch-control-position event. Furthermore, as shown in FIG. 2, while in a current mode, a switching transistor 16 is turned on, so that current will flow into a detector transistor 18, the magnitude of current flowing through detector transistor 18 is dependent on the intensity of light exposing on the detector, thus the magnitude of a current is read directly in determining a touch-control-position event.
For the light sensing circuit in a current mode, since the outputs of this circuit are signals of a light induction current, however, for the circuits responsible for system processing, the signals utilized are predominantly voltage signals, thus each of the respective read line 20 is connected to a resistor 22, as shown in FIG. 3, so that the output light induction current signals are converted into light induction voltage signals, and then that are transferred to a read circuit 24 via a read line 20 in determining the occurrence of a touch-control-position event. However, in this respect, in general, a large quantity of resistors have to be added additionally onto a printed-circuit-board (PCB), and that is quite inefficient, besides, the cost is high.
In view of the problems and shortcomings of the prior art, the present invention provides an embedded optical induction input device and a method implementing the same, so as to solve the afore-mentioned problems of the prior art.